--- a/media/libcubeb/gtest/test_record.cpp
+++ b/media/libcubeb/gtest/test_record.cpp
@@ -86,17 +86,17 @@ TEST(cubeb, record)
    * have one. */
   if (!has_available_input_device(ctx)) {
     return;
   }
 
   params.format = STREAM_FORMAT;
   params.rate = SAMPLE_FREQUENCY;
   params.channels = 1;
-  params.layout = CUBEB_LAYOUT_MONO;
+  params.layout = CUBEB_LAYOUT_UNDEFINED;
 
   r = cubeb_stream_init(ctx, &stream, "Cubeb record (mono)", NULL, &params, NULL, nullptr,
                         4096, data_cb_record, state_cb_record, &stream_state);
   if (r != CUBEB_OK) {
     fprintf(stderr, "Error initializing cubeb stream\n");
     ASSERT_EQ(r, CUBEB_OK);
   }
 

--- a/media/libcubeb/src/cubeb_pulse.c
+++ b/media/libcubeb/src/cubeb_pulse.c
@@ -743,30 +743,35 @@ to_pulse_format(cubeb_sample_format form
 }
 
 static int
 create_pa_stream(cubeb_stream * stm,
                  pa_stream ** pa_stm,
                  cubeb_stream_params * stream_params,
                  char const * stream_name)
 {
-  assert(stm && stream_params && stream_params->layout != CUBEB_LAYOUT_UNDEFINED &&
-         CUBEB_CHANNEL_LAYOUT_MAPS[stream_params->layout].channels == stream_params->channels);
+  assert(stm && stream_params);
+  assert(&stm->input_stream == pa_stm || (&stm->output_stream == pa_stm &&
+         stream_params->layout != CUBEB_LAYOUT_UNDEFINED &&
+         CUBEB_CHANNEL_LAYOUT_MAPS[stream_params->layout].channels == stream_params->channels));
   *pa_stm = NULL;
   pa_sample_spec ss;
   ss.format = to_pulse_format(stream_params->format);
   if (ss.format == PA_SAMPLE_INVALID)
     return CUBEB_ERROR_INVALID_FORMAT;
   ss.rate = stream_params->rate;
   ss.channels = stream_params->channels;
 
-  pa_channel_map cm;
-  layout_to_channel_map(stream_params->layout, &cm);
-
-  *pa_stm = WRAP(pa_stream_new)(stm->context->context, stream_name, &ss, &cm);
+  if (stream_params->layout == CUBEB_LAYOUT_UNDEFINED) {
+    *pa_stm = WRAP(pa_stream_new)(stm->context->context, stream_name, &ss, NULL);
+  } else {
+    pa_channel_map cm;
+    layout_to_channel_map(stream_params->layout, &cm);
+    *pa_stm = WRAP(pa_stream_new)(stm->context->context, stream_name, &ss, &cm);
+  }
   return (*pa_stm == NULL) ? CUBEB_ERROR : CUBEB_OK;
 }
 
 static pa_buffer_attr
 set_buffering_attribute(unsigned int latency_frames, pa_sample_spec * sample_spec)
 {
   pa_buffer_attr battr;
   battr.maxlength = -1;